Auger systems have been commonly used to move material from a silo or other storage structure. The stored material is often a flowable or semi-flowable solid material and is often granular in nature. Traditionally, bottom unloading auger systems have an auger that is located on the floor of the storage structure and is covered with stored material. To convey material from the storage structure the auger rotates about its linear axis to convey material along its flights from one of its ends toward a secondary conveying device. While the auger rotates about its linear axis it is also advanced through the stored material. There are two ways that bottom unloading auger systems advance the auger through the stored material:
1) Augers may rotate in a circular fashion through the stored material, conveying stored material to a discharge opening that is centrally located, then the material that flows though the discharge opening is fed into a secondary conveyor as shown in FIG. 1.
2) Augers may move in a linear fashion through the stored material, conveying the stored material to a discharge opening, then into a secondary conveyor as shown in FIG. 9.
The stored material exerts both static loads from the constant pressure of the material as well as dynamic loads as the auger conveys the material from the bottom of the storage structure. During use of the auger, voids may develop where stored material has been conveyed and that introduces asymmetric dynamic loads. These loads may not be predictable. There are many variables that dictate how flowable or semi-flowable solids in granular form may behave. Variables such as humidity, particle size, and compaction of the stored material affect how it will flow. At times, material may cake together, then suddenly cleave, and this can impart significant and unpredictable dynamic loads within the storage structure. Due to the unpredictable nature of loading, a designer of the storage structure employing a bottom unloading system must design the storage structure to be robust enough to handle the worst-case dynamic loading. This results in a structure that is over designed to handle loads it will rarely see. This has also meant that a designer of bottom unloading auger systems must necessarily design an auger system as an integrated package with a structure built together with the unloading system. As such, it is sometimes not possible to retrofit a bottom unloading auger system into an existing storage structure because sufficient reinforcement of an existing storage structure may not be possible or is cost prohibitive.